With Lauer and CBS' Charlie Rose off the air in disgrace, the $1 billion daypart is undergoing a massive shakeup.

NBC knew its day of Matt Lauer reckoning was coming. It just didn’t think it would end like this: Abrupt and in disgrace.

Lauer was in the middle of a two-year contract extension, signed last November, that kept him at the helm of “Today” through November 2018 at around $20 million a year. But Lauer’s tenure at “Today” frequently seemed precariously close to ending, as NBC groomed countless potential replacements while extending his contract.

Now, Lauer is the second morning-show anchor, following “CBS This Morning” host Charlie Rose, to be fired in recent weeks following reports and accusations of sexual harassment.

The departures could upend the tight morning-show race, particularly the competition for first place between “Today” and ABC’s “Good Morning America.” The daypart makes as much as $1 billion annually, and “Today,” as the demo leader, takes the largest slice of that cash pie.

During the just-completed November sweep, “GMA” was No. 1 with total viewers (4.3 million), followed by “Today” (4.2 million) and “CBS This Morning” (3.7 million). But in the adults 25-54 race — the news demo that advertisers care about the most — “Today” had the slight edge, with a 1.2 rating (equal to 1.5 million viewers), compared to “GMA” (1.1, or 1.4 million viewers) and “CBS This Morning” (0.8, or 979,000 viewers).

“GMA” already narrowed the gap with “Today” in the adults 25-54 demo vs. last year, and might be poised to overtake a Lauer-less “Today.”

But that all depends on what NBC does next. One TV news insider said NBC will likely focus on bringing in another male anchor to pair with Savannah Guthrie. “They’ll look at who’s clean [inside NBC] that they can put in right now,” he said. “Then they’ll look at local stations or national people from other places. They can get some of those guys to do it for cheap.”

Lauer has become a divisive figure, ever since the ugly departure of Ann Curry in June 2012. Not only was Curry’s ouster handled poorly, but Lauer was seen as someone complicit in the move (orchestrated by then-“Today” producer Jim Bell). That turned off some viewers, but most “Today” show viewers stuck by Lauer, and NBC — not wanting to rock the boat with its cash-cow morning show — did as well.

The Peacock’s attempts at grooming a successor for Lauer also hit speed bumps: Willie Geist, who had hosted the 9 a.m. hour of “Today,” eventually went back to MSNBC (and NBC’s “Sunday Today”) when it became apparent Lauer wasn’t going anywhere. “Access Hollywood” anchor Billy Bush was brought in to “Today” and was groomed to replace Lauer, until that infamous tape was of Bush laughing as Donald Trump admitted he sexually assaulted women. Former “GMA” news anchor Josh Elliott moved to NBC in 2014, presumably as a contender to replace Lauer, but he left the network a year later.

The Lauer scandal represents just the latest headache for NBC News, following last year’s Billy Bush debacle. Before that, in February 2015, Brian Williams was ousted from the “NBC Nightly News” after being called out for telling tall tales about his experience covering the Iraq War. And prior to that was “Today’s” messy Ann Curry removal. Most recently, Megyn Kelly’s new 9 a.m. show was seen as a disaster early on. Ironically, Kelly seems to have found her footing more recently, as she has placed greater emphasis on covering the nation’s (and Hollywood’s) ongoing sexual harassment and assault scandals.

Transitions are always difficult, but the fast Lauer and Rose exits leave behind many questions — like who knew what, and when they knew it, at those news organizations.

“Everyone’s known about Matt Lauer for years,” a source said. “I’m not surprised at some of the stories I’m hearing.” The same goes for Rose and countless others, insiders said, who haven’t been revealed yet — including some of the highest-paid hosts on TV.

The exits will also impact others, such as those anchors’ reps, and the networks may take a revenue hit if ratings decline and advertisers bail. “There are others who are going to lose their jobs over this,” said one observer.

On set, Guthrie opened the Wednesday edition of “Today,” along side Hoda Kotb (hastily brought in to share the desk) by admitting she was “devastated” by the news. “How do you reconcile your love for someone with the revelation that they have behaved badly?”